Sloped baffle

Bombaywalla ... I read as much of the discussions as I could before falling asleep at 1:30am in the morning. No surprise ... the physical science is way over my head. But I do have some take-a-ways that I would like to share. As a threshold matter, I ask whether we are "polishing a turd" as a practical matter.

As a warm up, there was some discussion which addressed whether using mics to record a musical presentation accurately captured the complex sound wave information that emanated from the multiple performers and instruments. One poster said that all a mic could do was sample a point in 3-D space, thereby missing a considerable amount of sonic/acoustical information. Even using multiple mics, while an improvement, still left much sonic information "on the floor," figuratively speaking.

Next ... the mastering process. So called sound engineers manipulate the sonic information that was imperfectly recorded at the live performance. The result is more sonic contortion and distortion.

Let's skip the next steps relating to the reproduction and transmission of source material via the various media used today (e.g., LP, CD, SACD, internet downloads, etc) and the electronics used to decode the information back into analogue electrical signals that are fed into the speakers. Suffice to say that additional contortions and distortions are infused into the analogue signal before it even reaches the speakers.

Ok, we're now at the speakers and a whole new set of issues present themselves. The bottom line challenge is that our speakers have to reproduce, more like reconstruct, the complex electrical analogue signals back into sound waves that are in phase through the whole harmonic spectrum.

And here the engineering problems and challenges are almost insurmountable: designing a system using multiple drivers that are mounted on a baffle (sloped or not sloped) to reproduce a point complex source sonic wave front that is the same as the original signal, even as modified by the sound engineers at the studio. My take-a-way is that the speaker designer can solve one problem, but create 5 more.

I don't want to embarrass myself by trying to faithfully restate what was said in the various posts. Suffice to say there are physical science challenges presented with every electrical and mechanical component that makes up a complete speaker system. At best ... what reaches our ears is the product of price point driven compromises that are ultimately limited by the laws of physical science.

My bottom line take-a-way is if "it" sounds good, "it" is good. Sure, we can and should audition speakers. Some will sound better than others. But to think any one speaker has perfectly solved all the engineering challenges and is able to faithfully reproduce a point source complex sound wave at the listening point is a pipe dream ... more like shear nonsense.

Perhaps that may be the reason many audiophiles and reviewers say that while specs and stats are informative ... in the end, what counts the most is how a speaker **subjectively** sounds to THAT listener, plugged into THAT listener's rig, positioned in THAT listener's sound room, and so forth.

And to me, that is what makes our hobby fun. Right now, I am listening to Eugene Ormandy, conducting the Philly Orchestra, performing a suite of various Saint-Saens selections. I am still enjoying the music even though it is being imperfectly reproduced by my imperfect rig.

Cheers,

Bruce

Bombaywalla, I have a follow up question. How are small speaker manufacturers able to design speakers without the benefit of the R&D budget, engineers, and testing facilities that some of the larger manufacturers have at their disposal.

For example, I recall reading that Focal, Harman and Paradigm have anechoic testing chambers, staffs of engineers and physical facilities that presumably enables these companies to make rational and informed choices when designing and building speakers. I also recall reading that these companies manufacture in-house their own drivers.

That is a question ... not a statement.

Bruce

Hi guys, I don't want to pretend to be The Expert on this subject, but I've built hundreds of speakers and have worked and designed along side some of the best back in my Marcof/SpeakerCraft days... so,
"but only if in combination with 1st order crossovers as used by Thiel and Vandersteen, revealing a coherent time-aligned step response"
1st order helps, but there is no speaker that is in complete phase at all frequencies... When you roll a speaker hard, it throws the driver out of phase just by the nature of steep slopes...
Remember a speaker rolls in and out of phase up and down the frequency ladder, once you choose your initial crossover point, you need to remeasure the drivers phasing up and down the scale with your first crossover in place , then choose another point that gets absolute phase at the crossover point. You may see a speaker that has a 350 & 3750 crossover point and you know that the tweeter can easily be crossed at 2500 or so, as long as the mid is smooth out to a given frequency, the designer may choose to take the frequency where absolute phase comes back into place. Also Impedance compensation helps control phasing a also. For that reason, I prefer impedance compensation, normally a driver sounds better when it needs compensation and compensation is used.
"I recall reading that Focal, Harman and Paradigm have anechoic testing chambers, staffs of engineers and physical facilities that presumably enables these companies to make rational and informed choices when designing and building speakers. I also recall reading that these companies manufacture in-house their own drivers".
Anechoic chambers help tremendously in measuring driver frequency and the effects that driver modifications have on a drivers frequency response, but Impedance & phasing are measurements that can be done without having a critical listening environment, I'm not trying to say that a great listening environment is not important, only that impedance and phasing can be handled without an anechoic chamber. Again, time alignment & correct phasing are keys to an imaging champ. I've kept it as simple as possible, I hope this helps,
Tim

Thanks Tim. I'm listening to a HD CD of Dave Brubeck's, "Time Out." Perhaps I'm just used to listening to sonic swill, but the imaging is more than satisfactory and the music is quite enjoyable. My fronts are Paradigm S8s (v3), with beryllium tweeters.

Btw, I think the original recording was made in 1959. Maybe that was the Golden Age of music recording, maybe not. But the HD CD redo sounds great.

As an Fyi, I bought the CD from the Acoustic Sounds web site. AS is located in Kansas. Very good source of music in all formats.

BIF

Getting back to the original question concerning sloped baffles and time alignment, Mofimadness commented:

"It is used to time align the drivers. Some manufacturers do this physically, (with the cabinet) and some do it electronically (in the crossover)."

No knowing a whole lot about speaker design, my guess is that it is more difficult and expensive to design and produce a speaker with a sloped baffle. Wouldn't that imply that there is some perceived advantage to doing so?